For the most part routers include adjustments for effecting vertical adjustment of the router sub-assembly relative to the base from which the sub-assembly is supported. However, these vertical adjustments may not be readily accomplished during use of the router and while guiding horizontal movement of the router with both hands. Accordingly, gradually varying depth routing in a controlled manner heretofore has not been possible when utilizing hand-held routers. Therefore, a need exists for structure whereby existing routers as well as newly constructed routers may have vertical adjustment structure incorporated therein enabling vertical adjustment of the router sub-assembly relative to the supportive base thereof while both hands of the operator of the router are holding the router handles.
Routers including conventional adjustment structures as well as other adjustable rotary equipment are disclosed in U.S. Pat. Nos. 2,855,963, 2,960,126, 3,160,133, 3,443,479 and 3,767,948.